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0. L. REDFIELD. PROCESS OF FORMING MATRICES.

5144.) avvlm UNITED STATES PATENLQ CASPER L. REDFIELD, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CHICAGO MATRIX MACHINE COMPANY.

PROCESS OF FORMING MATRICES.

SPECIFICATION forming part of Letters Patent No. 429,864, dated June 10, 1890.

Application filed December 6, 1889. Serial No. 332,756. (No model.)

To all whom it may concern:

Be it known that I, CASPER L. REDFIELD,

a citizen of the United States, residing at Chicago, in the county'of Cook and State of Illi- 5-nois, have invented certain new and useful Improvements in the Process of Forming Matrices; and I do hereby declare the following to be a full, clear, and exact description of the invention.

My invention relates to the art of forming matrices from which to cast stereotype-plates for use in printing, and more specifically to such matrices as are formed by the successive impressions of separate type-dies into a matrix material.

The object of the invention is to provide a method for the production of matrices that will be free from the usual imperfections and enable plates having their type-faces perfect to be cast therefrom. matrices made from type impressed The imperfections in in sequence usually arise from the partial filling or distortion of earlier impressions by the lateral displacement of the matrix material resulting from the forming of later impressions, and from such matrices it is impossible to cast plates having perfect type-faces. The impressions to enable desirable plates to be cast therefrom must have considerable depth in the matrix material as compared with the size of the faces of the characters themselves, and unless the body of the impressions back of the face is widened, portions of the impressions may not be reached by the metal, especially in the narrower lines, and

imperfect type-faces will be the result.

providing offsets in the impressions at suit-.

able distances back of the type-faces.

These offsets may be made to vary as to width and distance from the faces as the necessities of the case may require, and they may be provided only for the narrower stems of characters and for such portions of characters as arelikelytobe affected inj uriously bysucceeding impressions. Thus the hair-lines and feet of letters should be protected by the offset enlargements, while the heavy stems need no such protection; and, furthermore, I pre fer that the offsets on the forward sides (the sides adjacent to the succeeding impressions) should be wider and nearer the characterfaces than those in rear, and, also, that the character-faces in the impressions should have their stems (at least their wider stems) slightly convex in transverse section. in order that the characters on the plate cast therefrom may have their stems correspondingly concave, so as to present sharp margins and insure prints with sharply-defined outlines.

The preferable mode of forming the matrix is by type-dies of the character disclosed in my patent, No. 416,740, dated December 10, 1889, in which the dies are shown as having shoulders surrounding the feet and the hair-lines, or narrower stems, and the shoulders on the forward side are wider and nearer the typeface than on the opposite side. Such dies may be operated by means of any apparatus adapted to successively present and impress them into a matrix-body.

In the accompanying drawings, forming part of this specification, Figure 1 is a plan view of a portion of a matrix strip or body, upon which is impressed the word Milo, in conformity with my process. Fig. 2 shows a longitudinal section of the same through the middle of the letters on the line 0000 of Fig. 1; Fig. 3, a similar section on the line 3 y through the feet of the letters, showing only the im pressions for the letters i and l, and a die in position to form a second impression of the letter 1. Figs. 4 and 5 show, respectively, a

vertical section of a die for the letter 0, having its face concave in cross-section, and a sectional view of a matrix-body, showing the impression formed by such die.

In said drawings, 1 designates a portion of a matrix strip or body of paper or any suitable material, and M 2' Z 0 represent the respective character-impressions of the series shown therein. The impressions for these selected letters will sufficiently illustrate the method of forming the matrix, for the impressions for other letters and characters would show like characteristics. The letter faces or bottoms of the impressions are indicated by the reference-letters above given, and the side walls of the impressions by the figure 2. These walls and the walls at the head and foot of the impressions as well are preferably made to slope inward from the matrixsurface to the character-face, about as shown in Figs. 2 and 3, so that they will be considerably farther apart near the surface than toward the bottom. At both sides of the narrower stems of the letter M of the impression are offsets 3, which, as these stems are not likely to be affected by any crowding effect of a succeeding impression, may be of like width and depth, as shown. The letters i and l have the left or rear sides of their stems protected by like offsets 3, while their right or forward sides are protected by offsets at, that are wider and nearer the character-faces than the offsets 3. The sides of the letter 0 may be without the offsets, and the narrower and shallower offsets 3 provided only for the thinner lines of the head and foot of the letter. The feet of the letters have offsets 5 for the left or rear portions, that are wider, but of the same depth as those 8 for the stems, and for the right or front portions offsets 6, that are both wider and deeper or nearer the character-face than the offsets 3 and 5 5 and so with the heads of the letters offsets are provided at the rear similar to those designated 3 and 5, and at the front similar to those indicated by (i. For other letters than those shown the same process should be followed[. e., that of providing offsets in the matrix for the narrower lines and heads and feet of the character-impressions and making the forward otfsets wider and nearer the face than the others. In this manner the matrix material is compressed around the sides of the portions of the face-impression needing protection, and as each succeeding impression is made the wider offset portion in advance of an impression already made furnishes a compacted body upon which the typeface or the narrower rear offset of the latter impression may be formed without detriment to the character-face or materially narrowing the earlier impression as a whole. Thus, as will be apparent from Fig. 3, the formation of the letter 1 by the depression of the suspended die 7 can be effected without crowding over matrix material to materially interfere with the previously-formed impression 1, because of the offsets provided in the latter.

For the purpose of giving the sides of the main stems of characters in print a sharp outline the matrix impressions may be slightly convex transversely to the stems, as shown at 8 in Fig. 5. This may be done by having the die 9 made with its face transversely concave, as shown at 10, Fig. 4..

\Vhat I claim, and desire to secure by Letters Patent, is

1. The process of forming matrices for stereotype-plates, which consists in impressing dies in sequence into a matrix-body, and compressing material at both sides of the path of the type-face and forming offsets in the walls of the impressions, substantially as set forth.

2. The process of forming matrices for stereotype-plates, which consists in forming the impressions successively by dies and compressing the matrix material unequally at both sides of the path of the type-face to produce varying offsets in the walls, substantially as set forth.

3. The process of forming matrices for stereotype-plates, which consists in forming the impressions successively by dies and compressing the matrix material unequally at both sides of the path of the type-face to form offsets in the walls of greater width at the front than in rear of the character-face, substantially as set forth.

4. The process of forming matrices for stereotype-plates, which consists in forming the impressions successively by dies and compressing the matrix material unequally at both sides of the path of the type-face to form offsets inthe walls of greater depth at the front than in rear of the character-face, substantially as set forth.

5. The process of forming matrices for stereotype-plates, which consists in forming the impressions successively by dies and compressing the matrix material unequally at both sides of the path of the type-face to form offsets in the walls of greater width and depth at the front than in rear of the character-face, substantially as set forth.

6. The process of forming matrices for stereotype-plates, which consists in forming the impressions in succession by dies and compressing the matrix material at both sides. of the path of the type-face to form shoulders in the walls adjacent to the hairlines of the character-faces, substantially as set fort-h.

7. The process of forming matrices for stereotype-plates, which consists in forming impressions by successively-impressed dies and compressing the matrix material both laterally and parallel to the path of the typeface to form sloping walls and forming olfsets therein, substantially atset forth.

8. The process of forming matrices for stereotype-plates, which consists in forming the impressions therein successively by dies and making the stems of the character-faces the walls of its impressions sloping outward slightly convex in transverse section, snbfrom the character-faces and provided with 10 stantially as set forth. offsets, substantially as set forth.

9. A matrix for stereotype-plates havin its 5 impressions wider than the character-faces CASPER REDFIELD' and their walls provided with offsets, sub- Vitnesses: stantially as set forth. r F. W. HOYT, 10. A matrix for stereotype-plates, having SARA MILES. 

